This invention relates to a method for establishing and maintaining data communications between a mobile or portable computer and an established computer network.
Computers can be connected by data communications links to form a network for the exchange of data and sharing of file storage and printing resources. A computer, printer, or file server can be a "node" on the network, and each node can be identified by an individual address on the network. A number of networks can be joined to form an internet, and each network can be identified by an individual network number on the internet.
A stationary computer such as a desktop or mainframe computer is usually connected to a network by physical cables, connectors or taps, and the computer remains at a fixed location with a fixed address and network number during communications sessions.
A mobile or portable computer, when connected to a network, is usually connected by wireless, radio, or infrared communications links, and may suddenly disappear, move or appear at a new location out of reach of its previous network address. This type of moving operation by a mobile computer can be referred to as "roving" communications by a roving node.
Using the currently available computer network protocols, when a mobile computer obtains a new address and network number, the previous communication sessions will be lost and new communication sessions will have to be established. What is desired is a method that is compatible with the currently available computer network protocols, and can provide continued communications sessions for a mobile computer that obtains a new address and network number as it moves.
Previous designs to support mobile computers have contained several limiting beliefs: a belief that it is necessary to have high level software services for restarting communication sessions; or a belief that all computers on the network needed their communications software to be updated to support mobile computers. What is desired is a method that supports mobile computers without change to the currently operating computers and communications software.